Floor trap for burglar alarms



July 14, 1931. H. LOEDING FLOOR TRAP FOR BURGLAR ALARMS Filed May 11, 1929 2 sheets-sheet 1 Java/2hr fllifg/l oedziig July 14, 1931.

H. LOEDING FLOOR TRAP FOR BUHGLAR ALARMS Filed May 11, 1929 2 Sheets-Sheet 2 HZZ/ l 066/122 4 4M z w i 3 3 7% El 5 a T Z M aw m J a 6 4 m w a Patented July 14, 1931 PATENT OFFICE HENRY LOEDING, OF CHICAGO, ILLINOIS FLOOR TRAP FOR BUBGLAR ALARMS Application filed May 11, 1929.

This invention relates to electrically operated alarm signals and more particularly to devices known as burglar alarm traps.

One of the objects of the invention is the 5 provision of a device of the kind described which is adapted for use in any type of open or closed circuit burglar alarm system, and which can also be placed so as to sound an alarm upon opening a door, transom, ventila- Io tor, coal hole, or the like, and upon attempted entry through sky lights or other vulnerable areas in floors, walls, or ceilings, open or closed windows, and also by mounting in a gargage to cause an alarm to be sounded upon 31! movement of a car therein.

A further object of the invention is to provide a device of the kind described which is contructed to carry more than one circuit entirely through the device and where the removal of one wire, or a combination of wires, will cause the alarm to operate.

A still further object of the invention is the provision of a device of the kind described which is normally equipped with a trap cord having improved means to make tampering with a trap cord ineffective, such means being positive in its action, as for example, where a certain slight increase or decrease in tension on the trap cord will break a circuit and cause the alarm to sound, and a further increase or decrease of tension on the trap cord will cross the circuits and continue the operation of the alarm.

Still another object of the invention is the provision of an improved device controlled by a trap cord of the kind described, such device being operable to open the circuit and sound the alarm by a slight longitudinal movement of the cord in either direction.

Still another object of the invention is the provision of a device of the kind described which is capable of being utilized for fire alarm protection on either closed or open circuit, or may be used for combination burglar and fire alarm.

A further object of the invention is the production of a device of the kind described which is easy to manufacture and install, durable, reliable and highly satisfactory for its intended purpose.

Serial No. 362,314.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the description herein shown.

To this end my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in the claims.

Referring now to the drawings, wherein like reference characters indicate like or corresponding parts:

Fig. 1 is a View of a housing showing in detail a portion of the apparatus contained therein and also a diagrammatic view of the electric circuits;

Fig. 2- is a diagrammatic view of the lower portion of a room in which the device is installed;

Fig. 3 is 33 of Fig.

Fig. 4 is a sectional view along the line 44- of Fig. 3;

Fig. 5 is a large scale fragmentary view along the line 5-5 of Fig. 3 showing the window opening;

Fig. 6 is a view along the line 6-6 of Fig. 1;

Fig. 7 is a combination detail view and diagram of an alternative circuit; and

Fig. 8 is a view along the line 8-8 of Fig. 1.

Referring now more particularly to the drawings, the device is illustrated as partially contained in a casing or housing 10 having a removable lid 11. The housing 10 may be mounted in any convenient position in a room in which the device is to be installed but is preferably fastened near the floor and on one of the side walls of the room. The housing 10 is provided for this purpose with a mounting bar or plate 12. The bar 12 is fastened to one side of the housing 10 by rivets 14, the bar being spaced away from the housing by washers l3. Apertures 9 in the bar 12 are provided for the insertion of screws or nails to fasten the device to a door 01' window frame, or the like.

In Fig. 2, the device is shown as mounted in a room having oppositely positioned side a sectional view along the line 1- Walls and 16 and a floor 17. The device is so positioned that a wire 19, extending horizontally therefrom, is substantially eighteen inches from the floor 17. The wire 19 is fastened to a trap cord 18 by means of a connector 21. The connector 21 permits the cord 18 to be easily disconnected from the wire 19 as desired and to remain connected when subjected to ordinary tension resulting from a pull on the cord or wire. The cord 18 and the wire 19 provide a conductor extending across the room and are shown as fastened to the wall 16 by means of a hook or screw-eye 20. An inflammable cord 23 is fastened to the trap cord 18 in such a way as to permit a slight sag of the cord 18. In case of fire, combustion of the cord- 23 will permit the slack in the cord 18 to be taken up and operate the device to give a fire alarm. The cord 23 may be omitted, if desired and cord 18 stretched taut in which case the apparatus will function only as a burglar alarm. The trap cord 18 is preferably a braided. copper conductor suitably insulated and forming a portion of a circuit hereinafter called the circuit 22. The connector 21 in addition to being a fastening means provides an electrical connection between the wire 19 and the trap cord 18. The'wire 19 and the connector also form a part of the closed circuit 22.

A substantially sector-shaped trap arm assembly, generally designated by the numeral 25 is pivotally mounted in the housing 10 as best shown in Figs. 1 and 7. The as sembly 25 is rotatable about a pivot or bolt 26, between limits determined by stop bolts 27 and 28. The bolt 28 extends through the housing 10 transversely and is utilized by threading a nut 45 on the outer end as a means for fastening a removable lid 11 upon the body of the housing. The pivot bolt 26 is fastened to the bottom of the housing by oppositely positioned nuts 33 and 34. A collar 35 provides packing between the head of the bolt 26 and the inside nut 33. The trap assembly 25 is mounted on the bolt 26 and the collar packing 35 gives the requisite stability to the assembly mounting. The assembly 25 further comprises contact plates 36 and 37.

The plates 36 and 37 are mounted upon one of a pair of sector-shaped insulating plates 38 as best shown in Fig. 3. The insulating plates 38 may be constructed of a phenolic condensation product, or any other suitable insulating material and are fastened. together by a pair of pins 39. The plates 38 are positioned one on each side of a metallic sector-shaped plate 46 through which the pins 39 extend. A conducting plate 42 is positioned on the assembly 25 opposite to the contact plate 36. A pin 40, extending through the insulating plates 38, provides means for fastening the oppositely positioned plates 36 and 42 together. A collar 41 mount-' ed upon the pin serves as a spacer between the insulating plates 38. The pin 40 is of conducting material and forms an electric connection between the plates 36 and 42. A metallic plate 43, preferably of spring brass or other resilient material, is mounted on the assembly 25 adjacent to the plate 42 but'normally disconnected therefrom. The 7 plate 43 is electrically connected with plate 37 by means of a fastening bolt 52.

The wire 19 is fastened to the plates 38 in any desired manner and extends from its fastening to the left as observed in Fig. 1. The wire 19 electrically connects the collar 41 for all positions of the assembly.

An arm 47, projecting from the plate 46, has an aperture 49 to which one end of a tensile spring'48 is connected. The other end of the spring 48 is fastened to a lug 50, the lug being connected by any suitable means to one edge of the housing 10. The trap arm as sembly 25 is held in its full line position of Fig. 1 by the resilience of the spring 48. The pull exerted by the spring 48 upon the arm 47 tends to rotate the assembly 25 in clockwise direction, which tendency is resisted by the wire 19 and the cord 23 or the 'cord 18 when the wire and cord are stretched taut, as indicated in Fig. 2. The spring 48 yields and permits the assembly 25 to be rotated in counter-clockwise direction to the dotted line position of Fig. 1, if a pull is exerted upon the wire 19. Upon release of the wire 19, by loosening the cords 18 or 23, as the case may be, the spring 48 will rotate the assembly 25 in clockwise direction to the extreme right hand dotted line position of Fig. 1. It is obvious that a push or pull transversely on the cords 18 or 23 will rotate the assembly 25 in counter clockwise direction and that loosening or disconnection of the cords 18 or 23 from the wire 19 will permit clockwise rotation of the assembly 25 by reason of the pull exerted by the spring 48.

A non-conducting plate is mounted on the inside face of the lid 11, as best shown in Figs. 3 and The plate 55 is fastened to the lid 11 by a plurality of rivets or pins 56. A pair of contact arms 29 and 31, preferably constructed of brass or bronze, are suitably mounted on the interior of the lid 11 by terminal posts 39 and 32, respectively. The posts 30 and 32 are insulated from the housin 10 in any desired manner. \Vhen the lid is in closed position, the free ends of the arms 29 and 31'engage and form a wiping contact with the trap arm assembly 25.

When the trap arm assembly 25 is in the full line position of Figs. 1 and 7, the arm 29 engages the arm 36. The plate 31 engages the plate 37 for all positions of the assembly 25. Upon rotation of the assembly 25 in counter-clockwise direction to the dotted line position shown at the left in Figs. 1 and 7, the arm 29 is brought into contact with the right hand projection of the plate 37. The plate 37 thereby forms a conductor connecting the free ends of the arms 29 and 31. Similarly, upon movement of the assembly in clockwise direction, the free end of the arm 29 will engage the left hand projection of the plate 37 and the plate will thereby again form an electrical conductor between the arms 29 and 31. Since the plates 36 and 37 are insulated from each other by the plate 38 in which they are mounted, it is obvious that the arms 29 and 31 are electrically disconnected for the full line position of the assembly 25 and are electrically connected for either of the dotted line positions therein shown.

A bus bar 57, best shown in Fig. 1, is mounted on the inside face of the insulating plate 55. The bar 57 is of conducting material and electrically connects a post 58 with a post 32 upon which the arm 31 is mounted. A conductor or wire 59 having an insulated covering connects the post 58 with a tamper spring or contact plate 61, as shown in Figs. 1 and 7.

" The wire 59 is shown as held suspended by a guide clip 60 suitably fastened on the stop bolt 28 although such clip could be omitted and the wire extend directly from post 58 to the plate 61.

The plate 61 projects upwardly a substantial distance from its mounting and is normally spaced apart from and parallel with a supporting spring plate 62. The plates 61 and 62 have a common mounting comprising a plurality of non-conducting plates 64 which insulate the plates 61 and 62 from each other.

The plates 64 provide a fixed mounting for the spring plates 61 and 62 and for this purpose are rigidly fastened to the housing 10 by a plurality of screw bolts 65. The shanks of the bolts 65 are enclosed by an insulated covering (not shown).

A generally annular-shaped metallic guide member 63 is mounted on the upper free end of the plate 62. The guide member 63 converges outwardly and projects through an aperture formed for that purpose in a side wall of the housing 10 without contacting the housing, as best shown in Figs. 1 and 6. The

-: wire 19 extends through an aperture 54 in the guide member 63. The aperture 5 1 is large enough to permit the wire to freely move therein. The mounting of the member 63 and the plate 62 provides complete insulation of the wire 19 from the housing 10. The

arrangement of the plates 61 and 62 in parallel and spaced apart relation and the particular construction of the wire guide 63 is hereinafter more particularly explained.

The middle portion of the assembly 25, adjacent to the back wall of the housing 10 is provided with a narrow radially extending white or luminous stripe 70. A narrow window opening 66 is provided in the back wall of the housing 10 in such position that the stripe 70 registers with the window 66 when the assembly 25 is in the full line position of Figs. 1 and 7 wherein the arms 29 and 31 are insulated from each other. The remainder of the exposed face of the assembly 25 may be painted black or some other contrasting color.

The plate 43 is positioned between the window opening 66 and the plate 42. The Window opening 66 is closed by a strip 68 of mica, glass or other transparent material suitably mounted between apertured plates 67. The plates 67 are fastened to the adjacent wall of the housing by rivets 69. WVhile such devices are desirably equipped with a window to indicate when the device is properly set, such a window adjacent the assembly 25, provides an opening through which a nail or similar object may be inserted for the purpose of holding the assembly against movement and thereby preventing the alarm from operat ing. The possibility of such manipulation of the device by an unauthorized person is avoided by positioning the plate 43 between the assembly 25 and the window 66, since the object thus inserted will contact with and force the plate 4-3 into contact with the plate as, thereby crossing the circuit and starting the alarm, as hereinafter more particularly explained in the description of the circuit diagrams.

The arms 29 and 31 are connected with a battery 74: by two closed circuits both shown in Fig. 1. Battery 74: is preferably of small voltage and is directly connected with the arm 29 through the circuit The circuit 22 is shown as extending through a protective unit (5 which may be a window, a transom or any other device, which, upon movement will open the circuit. units 7 5 may be provided or such units may be omitted entirely. Upon the assembly 25 taking either of the dotted line positions as shown in Fig. 1, current will pass from the conductor 22 into the post 30, next through the arm 29, to the contact plate 37, and from the contact plate 37 through the arms 31 and ice A plurality of g'.

the post 32 into the bus bar 57 which serves as a conductor between the post 32 and the post 58. with the battery 74 and passes through a circuit resistor 78 of any desired resistance.

The operation of the device is as follows: l/Vhen the trap cord 18, either wi. out the inflammable cord 23. is j l protective position with the cord 18 f tened or withto the hook or screw-eye 26. the trap inhly 25 is in the full line position of F In this poistion, the free ends of wiping contact arms 29 and 31 are not electrically connected through tl as bly the protective or supervisory cu nit connects the battery 74 through a conductor forming part of a so called feed circuit 22 with the terminal post 30, the circuit passing through pro- A circuit 77 connects the post 58 2..

tective' units ifany. The current then flows through-arm 29 into contact plate 36 and from contact plate136 through pinO and collar 4l1into the trap wire 19. The current passes from trap wire 19 through the from magnet 76 through conductor forming part of a circuit 77 into terminal post From terminal post 32 the current travels through the bus bar 57 to the post 58'. The post 58 is connected with the battery 7 a through a conductor forming a portion of the so called permanent circuit 77, in which the circuit resistor 78, is positioned.

The protective, or supervisory feed cir' cuitthus described, may be shunted out dun ing business hours by closing a shunt switch 88 positioned in a shunt circuit 87. Vhen the shunt switch 88 is closed, current travels from battery 7 4: direct to relay 76 and through the permanent circuit 77 including the bus bar 57,-the post 58-and the resistor 78.

Rotation of the trap assembly 25, as observed in Fig. 1, either clockwise or counterclockwise from the full line position, first breaks the circuit 22 by disconnecting arm 29 from plate 36 and moving the arm into wiping contact with the adjacent insulator plate 38 at some point between the plates 36 and 37. This position of the arm 29', may result either from a slight loosening or a slight pull on the wire 19, such as would follow from bumping or otherwise contacting with the cords'18 and 23. The current then no longer passes through the wire 19 into the circuit 22,: and as a result'th'e relay magnet 76 is de-energized. De-energizing of themagnet 76 permits the spring 79 to pull the pivoted armature 81 against the relay point 82. The spring 79 is fastened to any suitable fixed mounting 80, such mounting preferably being a portion of the relay assembly of which the magnet 76 forms a part.

Contact of armature 81 with relay point permits the current to flow from a battery 86 through a gong circuit 84, the relay point 82, the armature 81, the circuit 71, and then into battery 74, thereby sounding the gong 83, or any other alarm device which may be positioned in the circuit 84. The alarm bell 83' switch 72 is operable to open and close the gong circuit 8 L when desired. The battery 86 is of relatively high voltage or SUillClGIlt to provide the power requisite to operate the alarm bell'or gong 83. The battery 74 may be of relatively low voltage, but must be suflicient to keep the relay magnet coil 76 energized. A shunt circuit 95 for setting the relay 76 is opened and closed by a switch 96. I 7

Further rotation of the assembly 25 away from its full line position and into either of the dotted line positions of Fig. '1 may result from a pull on the wire 19 or release of the wire following accidental contact with the cords 18 or 23, or the intentional pulling on, loosening, or disconnection of the cords fronr the wire. In either of the dotted line positions of the assembly 25, both of the arms 29 and 31 have wiping contact with the plate 37 resultingin crossing the circui 22 with the circuit 77. lVhen the circuits 22 and 77 are thus crossed, current flows as follows: From the battery 7 1, through the circuit 22, into and through the post 30, the arm 29, the plate 37, the arm 31, the post 32, the bus bar 57, the post 58, the circuit 7 7, through the resistor 78 back to the battery 74:, thereby de-energizing the relay and closing the alarm circuit.

The supporting spring plate 62 and the tamper spring contact plate 61 provide im proved means intended to prevent a burglar or other unauthorized person from attempting to hold the wire 19 against'longitudinal movement and resulting rotation of the trap assembly 25, either by placing a wedge in the" aperture 54 or a clip orsimilar object on the wire 19, immediately outside of the housing '10, for the purpose of shunting the circuit. T he pull of the spring 48 exert-ed through the assembly 25 upon the wire 19 tends to cause the wire to move inwardly upon anyslackein ing of the cords 18 or 23 following such wedgi'ng or clipping operations. Even a slight'inward movement 'oi'tho wire 19, when thus wedged or fastened with a clip, will cause a corresponding movement of the guide member 63 inwardly of the housing 10 and thereby bring the plate 62 into contact with the upper curved end of the plate 61. Since only a slight movement of the wire 19'brings the plate 62 into contact with the plate 61, such contact of the plates occurs before arm 29 has moved ofl of the plate 36 and while arms 29 and '31 remain electrically disconnected by way of the assembly 25. An insulating plate 97 is mounted on the casing 10 adjacent the free end of the plate 62 to prevent accidental contact of the plate with the housing. 7

Upon contact of the plates 61 and 62 current travels from battery 7 4 through the circuit 22, the post 30, the arm 29, the plate 36', the pin lO and the collar 41 into the wire 19. Since the wire 19is in electrical contact with the wire guide member 63, and the current takes the line oi least resistance, it will travel from the wire and guide member through plates "2 and 61 into the conductor59 and to the post 58. From post 58 the current travels through circuit 77 back to the battery 74. Since current no longer flows from the wire 19 into the circuit 22, the relay 76 is de-energized and the armature 81 is pulled to its dotted line positiiai, thereby permitting current to flow e 'y 86 into the gong circuit 84 are alarm bell 83 to sound.

it an attempt is made to hold the trap assembiy against rotation by inserting a nail or other snarp object, through the lip (38 into holding engagement with the ass ibly, such object will first come into contact with the plate 43. The plate 4L3, being resilient, will thereby be pushed into contact with the plate Since the plate 43 is connected with the plate 36 by a bolt 52, co ct of the plates and 41:2 crosses the circuits 2:4 nd 77 through the assembly 25. lVith the plates 42 and 43 thus in contact, cur rent passes from the battery 74 through the conductor into arm 29, through plate 36, pin -29, the plate 42, plate t3, the bolt 52, and into piate 37. From plate 37 the current passes through arm 31, post 32, bus bar 57, post 58, and circuit 7 7 back to battery 74. mince the current no longer passes through the wire 29 and the circuit 22, the relay 76 is tie-energized. The spring 79 thereupon pulls the armature 81 into contact with the point 82, closing the o'ong circuit 8% and permitting current to flow from the battery 86 and sound the alarm bell 83.

Removal of the lid 11 from the housing 10 carries with it the contact plates 29 and 31.

Removal of the plate 29 breaks the circuit flowing through plate 36 into wire 19. The breaking of the circuit in this manner produces the same result as cutting the wire 19 or the cord '18 in the manner described as fol- ,7 rial rotation of the trap assembly. ig. 7 the device is shown as connected with a normally open circuit, wherein the trap assembly is held in its full line position by an easily broken, fragile, non-conducting string or cord 89. A circuit 92 connects the arms and 31 with abattery 93. F or the full line position of the assembly the circuit is opened and by rotating the trap assembly 25 to either of its dotted line positions, the arms 29 and 31 will be electrically connected through the plate 37 and the circuit closed. Closing of the circuit 92 will cause the alarm bell or gong 91 to sound. A switch is also provided to open and close the circuit 92 as desired.

Thus it will be seen that the device is operable in connection with a trap cord of metallic or conducting material to carry two closed circuits therethrough and upon breaking either of the circuits or crossing the one circuit with the other to sound the alarm, and upon equipping the device with a breakable trap cord of non-conducting material it is op b e with an open circu it which will close and sound the alarm upon breaking the cord or exerting a pull thereon.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein described and shown, or uses mentioned.

\Vhat I claim as new and desire to secure by Letters Patent is:

1. In apparatus of the kind described, a casing, a rotatable switch member mounted in the casing, a trap cord extending through an aperture in one wall of the casing, said cord having one end fastened to the switch member, and the other end fastened to a fixed member, a spring fastened to said switch member and yieldingly holding said cord stretched tight, an annular guide member mounted in said aperture in said casing wall, said cord passing through said annular member, a spring plate having one end fixedly mounted on and insulated from said casing, said annular member mounted on the other end of said plate, a contact member adjacent to said plate, said cord being operable to move said plate to connect with said contact member upon release of said cord after wedging the cord in said guide member.

2. In an apparatus of the kind described, a casing, a rotatable switch member mounted in the casing, a trap cord extending through an aperture in one wall of the casing, said cord having one end fastened to the switch member and the other end fastened to a fixed member, a spring fastened to said switch member and yieldingly holding said cord stretched tight, an annular guide member mounted to move freely in said aperture and out of contact with said casing in a manner to prevent wedging contact of said cord with the wall of said casing, said cord passing through said annular member, a spring plate having one end fixedly mounted on and insulated from said casing, said annular member mounted on the other end of said plate, a contact member adjacent to said plate, said cord being operable to move said plate to contact with said contact member upon release of said cord after wedging the cord in said guide member.

3. In an apparatus of the kind described, a casing, a rotatable switch member mounted in the casing, a trap cord extending through an aperture in one wall of the casing, said cord having one end fastened to the switch member and the other end fastened to a fixed member, a spring fastened to said switch member and yieldingly holding said cord stretched tight, an annular guide member mounted in said aperture and extending therethrough beyond the outer face of the casing wall in a manner to prevent wedging contactioii said cord with thevwall of. said casing, said cord passing through said an- 7 nular'member; a spring plate havin one end fixedly. mounted on and insulated fi'om said casing, said annular member mountedon the othen end of saidplate, econtact member-ad: jacent to said plate, said/00rd being operable tomove said plate to contact with said contact member upon release of said cord after wedging the cord in said guide member.

In witness whereof, .I I hereunto subscribe my name this 6th day of'May, A. D. 1929. HENRYJLOEDING. 

